A well known and widely used baker's oven comprises a number of superimposed oven compartments with individual oven doors at the front. Each compartment generally includes two turntables onto which bakery goods including bread pins are loaded.
The oven compartments are heated by electric heating elements in the bottom and top of the compartments. The heating elements are formed as single heating units comprising a number of parallel arms connected in series by U-shaped elements. The parallel arms extend from the oven door to the rear of the compartment and are spaced across the width of the oven.
The controlled introduction of steam into the oven compartment of bakers' ovens is well known. Steam can be used to create glazed buns, “split” crusts or bakery products such as bread and rolls One means of introducing steam into bakers' ovens is to use external steam generators and introduce the steam into the oven through a conduit connecting the steam generator to the oven. This method of steam generation requires an additional steam generator and is thought to be inefficient, not only in terms of the overall heat requirements of the baking and steam generation process but an external steam generator uses up valuable bakery space.
In recent years to avoid the need for external steam generators, water has been sprayed into the oven compartments for conversion into steam. This creates problems for designers and manufactures of bakers' ovens in that the heat energy required to convert water into steam must not be so large as to cause the internal temperature in the compartments to drop more than say 5-10° C., or the quality of the finished baked products may be adversely affected.
Secondly, all of the water must be converted into fine steam before it comes into contact with the bakery products, as impingement of even very small water droplets on the surface of the bakery products adversely affects the surface appearance thereof.
A further complication has arisen with the adoption of ceramic surfaces, e.g. ceramic tiles, on the oven turntables on which the products are baked. If the steam is sprayed directly at the ceramic surfaces, they will absorb the steam and the quantity of steam available to the bakery products is minimised.
Australian Patents Nos. 666365, 666633 and 669838, all in the name of APV Australian Pty Ltd, all disclose an internal steaming assembly for a bakers oven in which the parallel rods of the lower heating element in the oven compartments are positioned in the vicinity of a ballast bar. Water from a water supply pipe is sprayed onto the heated ballast bar at the front of the oven compartment and the resulting generated steam left to circulate in the oven compartment. Apart from a plate over the section of the ballast bar adjacent the water pipe to prevent splashing, the ballast bar is not covered and is exposed to debris such as product overflow falling from the rotating turntables, onto the hot heating rods. This debris bakes onto the heating rods and ballast bars and must be regularly cleaned from the rods and ballast bars for heating efficiency and product quality reasons.